This relates to integrated circuits, and more particularly, to testing integrated circuit packages.
An integrated circuit package typically includes a package substrate, an integrated circuit die mounted on the package substrate, and some type of package housing material formed over the integrated circuit die on the package substrate to seal the integrated circuit die within the integrated circuit package. An array of solder balls (commonly referred to as a ball grid array or BGA) is often formed at the bottom of the package substrate for use in facilitating input-output communications with external components.
Consider a scenario in which a first solder ball in the ball grid array is electrically connected to a second solder ball in the ball grid array via an intra-package path passing through one or more integrated circuit die within a single package. The first and second solder balls and the intra-package path coupling the first solder ball to the second solder ball can sometimes be referred to collectively as a BGA daisy-chain net pair.
It is generally desirable to be able to test the integrated circuit package to ensure that all the solder balls in the ball grid array are properly manufactured (i.e., properly connected to the integrated circuit die without any inadvertent short or open circuits). Conventional test systems, however, do not offer a simple automated way for performing I-V (current-voltage) curve tracing and for making electrical measurements for detecting opens/shorts across any desired BGA daisy-chain net pair. Existing package test systems for isolating manufacturing faults are extremely time-consuming, especially for packages with higher than average pin counts. Moreover, current test systems cannot be adapted to test packages with different pin counts, and as a result, separate test board designs are required for testing different types of packages.